you need to keep replacing the drive bays on that case (hard disk vibrations kill em) --- they use the the exact Gillette model
the price guess seems accurate but don't forget the most important factor when it comes to a geek selling their kit ...
the level of the computer literacy of the buyer ... if this is low they will not have any idea of computer tech and related pricing and if they have low computer literacy you will be round every 2 weeks removing spy ware ( you may want to factor that into your price)